P
US8058214B2ActiveUtilityPatentIndex 52

Process for making shock absorber fluid

Assignee: SWARTELE CHANTAL RPriority: Jun 28, 2007Filed: Jun 28, 2007Granted: Nov 15, 2011
Est. expiryJun 28, 2027(~1 yrs left)· nominal 20-yr term from priority
Inventors:SWARTELE CHANTAL RROSENBAUM JOHN MDE WEERDT MARC JPLAETINCK THOMASMILLER STEPHEN JSZTENDEROWICZ MARK L
C10M 2209/084C10N 2030/18C10N 2030/08C10N 2030/00C10M 169/04C10M 2205/028C10N 2070/00C10M 2205/026C10M 2205/04C10N 2030/68C10M 2205/173C10N 2040/08C10N 2020/02C10M 177/00C10N 2030/02C10N 2020/04C10M 171/00
52
PatentIndex Score
3
Cited by
17
References
35
Claims

Abstract

A process to make a shock absorber fluid having improved performance properties, the properties including an air release after 1 minute by DIN 51381 of less than 0.8 vol %, a kinematic viscosity at 100° C. less than 5 mm 2 /s and an aniline point greater than or equal to 95° C., or meeting the specifications for Kayaba 0304-050-0002 or VW TL 731 class A. The shock absorber fluid is made by blending a base oil having less than 10 wt % naphthenic carbon and a high viscosity index with low levels of (or no) viscosity index improver and pour point depressant.

Claims

exact text as granted — not AI-modified
1. A process to make a shock absorber fluid, comprising:
 a. selecting a base oil fraction having: consecutive numbers of carbon atoms, a kinematic viscosity at 100° C. between 1.5 and 3.5 mm 2 /s, a pour point less than −35° C., from greater than 5.8 wt % up to 27.5 wt % total molecules with cycloparaffinic functionality, and less than 10 wt % naphthenic carbon; and 
 b. blending the base oil fraction with additives and less than 3.0 wt % combined viscosity index improver and pour point depressant, based on the total shock absorber fluid, to produce the shock absorber fluid having an air release after 1 minute by DIN 51381 of less than 0.8 vol %. 
 
     
     
       2. The process of  claim 1 , additionally comprising hydroisomerizing a waxy feed to make a product with increased branching and lower pour point; wherein the product comprises the base oil fraction. 
     
     
       3. The process of  claim 2 , additionally comprising hydrofinishing the product to reduce the olefin content in a hydrofinished product to less than 10 wt % and the aromatics content to less than 0.1 wt %. 
     
     
       4. The process of  claim 3 , additionally comprising fractionating the hydrofinished product to produce the base oil fraction. 
     
     
       5. The process of  claim 1 , wherein the base oil fraction has between about 1 and about 5 wt % naphthenic carbon. 
     
     
       6. The process of  claim 1 , wherein the base oil fraction is Fischer-Tropsch derived. 
     
     
       7. The process of  claim 1 , wherein the shock absorber fluid has an air release after 1 minute by DIN 51381 of less than 0.5 vol %. 
     
     
       8. The process of  claim 1 , wherein the shock absorber fluid additionally has a viscosity index greater than or equal to 129, and a Brookfield viscosity at −30° C. less than 1,000 mPa.s. 
     
     
       9. The process of  claim 1 , wherein the base oil fraction comprises a pour point reducing blend component. 
     
     
       10. A process to make a shock absorber fluid, comprising: blending a Fischer-Tropsch derived base oil having a kinematic viscosity at 100° C. less than 3.0 mm 2 /s, from greater than 5.8 wt % up to 27.5 wt % total molecules with cycloparaffinic functionality, and a viscosity index greater than 121 with an effective amount of at least one additive; wherein the shock absorber fluid has a kinematic viscosity at 100° C. less than 5 mm 2 /s, an air release after 1 minute by DIN 51381 of less than 0.8 vol %, and an aniline point greater than or equal to 95° C. 
     
     
       11. The process of  claim 10 , additionally comprising the step of blending the Fischer-Tropsch derived base oil with less than 4.0 wt % combined viscosity index improver and pour point depressant, based on the total shock absorber fluid. 
     
     
       12. The process of  claim 10 , additionally comprising the step of blending the Fischer-Tropsch derived base oil with a pour point reducing blend component. 
     
     
       13. The process of  claim 10 , wherein the Fischer-Tropsch base oil additionally has between about 1 and 10 wt % naphthenic carbon. 
     
     
       14. The process of  claim 13 , wherein the Fischer-Tropsch base oil has between about 1 and about 5 wt % naphthenic carbon. 
     
     
       15. The process of  claim 10 , wherein the Fischer-Tropsch base oil has a VI such that X in the equation VI=28×Ln(Kinematic Viscosity at 100° C.)+X, is greater than 90. 
     
     
       16. The process of  claim 10 , wherein the shock absorber fluid has a flash point greater than 195° C. 
     
     
       17. The process of  claim 10 , wherein the Fischer-Tropsch derived base oil has:
 a. a kinematic viscosity at 100° C. between 1.5 and 4.0 mm 2 /s; and 
 b. a Noack volatility less than its Noack Volatility Factor defined by the equation: NVF=160 −40×(kinematic viscosity at 100° C.). 
 
     
     
       18. The process of  claim 17 , wherein the Fischer-Tropsch derived base oil has:
 a. a kinematic viscosity at 100° C. between 2.4 and 3.8 mm 2 /s; and 
 b. a Noack volatility less than an amount defined by the equation:
   900×(kinematic viscosity at 100° C.) −2.8 −15.
 
 
 
     
     
       19. A process to make a shock absorber fluid, comprising:
 a. selecting a Fischer-Tropsch derived base oil that is an XLN grade having a kinematic viscosity at 100° C. between about 2.3 and about 3.5 mm 2 /s, an XXLN grade having a kinematic viscosity at 100° C. between about 1.8 and 2.3 mm 2 /s, or a mixture of the XLN grade and the XXLN grade, and having from greater than 5.8 wt % up to 27.5 wt % total molecules with cycloparaffinic functionality; 
 b. blending the Fischer-Tropsch derived base oil with an effective amount of at least one additive; 
 wherein the shock absorber fluid meets the specifications for Kayaba 0304-050-0002 or VW TL 731 class A, and has an air release after 1 minute by DIN 51381 of less than 0.8 vol %. 
 
     
     
       20. The process of  claim 19 , additionally comprising the step of blending the Fischer-Tropsch derived base oil with a pour point reducing blend component. 
     
     
       21. The process of  claim 19 , wherein the shock absorber fluid has an aniline point greater than or equal to 95° C. 
     
     
       22. The process of  claim 19 , wherein the shock absorber fluid has an air release after 30 seconds by DIN 51381 of less than 0.8 vol %. 
     
     
       23. The process of  claim 19 , wherein the effective amount of at least one additive comprises less than 4 wt % combined viscosity index improver and pour point depressant, based on the total shock absorber composition. 
     
     
       24. The process of  claim 1 , wherein the less than 3.0 wt % combined viscosity index improver and pour point depressant comprises 0.0 wt % pour point depressant. 
     
     
       25. The process of  claim 11 , wherein the less than 3.0 wt % combined viscosity index improver and pour point depressant comprises 0.0 wt % pour point depressant. 
     
     
       26. The process of  claim 19 , wherein the effective amount of at least one additive comprises 0.0 wt % pour point depressant. 
     
     
       27. The process of  claim 1 , wherein the base oil fraction has greater than 20 wt % total molecules with cycloparaffinic functionality. 
     
     
       28. The process of  claim 10 , wherein the base oil has greater than 20 wt % total molecules with cycloparaffinic functionality. 
     
     
       29. The process of  claim 19 , wherein the base oil has greater than 20 wt % total molecules with cycloparaffinic functionality. 
     
     
       30. The process of  claim 10 , wherein the base oil has a pour point less than −35° C. 
     
     
       31. A process to make a shock absorber fluid, comprising:
 a. selecting a base oil fraction that is not an oil based on PAO, having: consecutive numbers of carbon atoms, a pour point less than −35° C., greater than 5.8 wt % total molecules with cycloparaffinic functionality, and between 2 wt % and less than 5 wt % naphthenic carbon; and 
 b. blending the base oil fraction in an amount greater than 95 wt % of the total shock absorber fluid, with additives; 
 wherein the base oil is an XLN grade having a kinematic viscosity at 100° C. between about 2.3 and about 3.5 mm 2 /s, an XXLN grade having a kinematic viscosity at 100° C. between about 1.8 and 2.3 mm 2 /s, or a blend of the XLN grade and the XXLN grade; and 
 wherein the shock absorber fluid has a flash point greater than 195° C. and a kinematic viscosity at 100° C. less than 5 mm 2 s. 
 
     
     
       32. The process of  claim 1 , wherein the shock absorber fluid has a shear loss in a 20 hour KRL shear stability test of 0.8% or less. 
     
     
       33. The process of  claim 10 , wherein the shock absorber fluid has a shear loss in a 20 hour KRL shear stability test of 0.8% or less. 
     
     
       34. The process of  claim 19 , wherein the shock absorber fluid has a shear loss in a 20 hour KRL shear stability test of 0.8% or less. 
     
     
       35. The process of  claim 31 , wherein the shock absorber fluid has a shear loss in a 20 hour KRL shear stability test of 0.8% or less.

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